Machine for sizing, truing, and polishing bars and tubes



w. slEsr-:Rls'r 2,132,976 MACHINE FOR srzINcr, TRUING. AND PoLIsHING BARS AND TUBES Oct. 11, 1938.

Filed Oct. 21, l19555 2 Sheets-Sheet 1 .Z j a. W 5 ZN, .5 M9

Patented Oct. 11, 1938 UNiTED STATES PATENTy OFFICE MACHINE Fon sIzING.- 'momo'. Aim Pousnmc BARS AND TUBES Walter Siegerlst, St. Louis, Mo. i Application octcbcr z1.1935, serial Nc. 45,892

7 clam (o1. so-is) satisfactory is to draw the cold stock through dies, but it is not practicable for bars of large diameter. However, this cold drawing operation is not suitable for certain steels and other metals and it has certain disadvantages, such as the danger of pulling the stock in two, the intensifying of surface defects and the bending of the stock, and the economic disadvantage that it requires the pickling ofv thematerial and requires a separate die for every size of stock. The'object of the present invention is to devise a machine which will size, true and polish round'bars and tubes and still avoid the above mentioned disadvantages of coldv drawing. The invention.

consists principally in a stand of longitudinally concave work rolls so designed and arranged that they make straight linecontact with the work throughout their full operative length. It

also consists in the rolls and in the combinations and arrangements oi parts hereinafter described and claimed. i

In the Aaccompanying' drawings in which like reference numerals refer to like' parts wherever they occur, i

Fig. 1 is a side elevation of a machine embodying my invention;

Fig. 2 is a longitudinal vertical section cf the main portion of the machine on a plane between the work rolls and showing the work stock in position;

Fig. 3 isa horizontal section of the work rolls and work stock on the line 3--3 of Fig. 2;

Fig. 4 is a vertical cross section of the work'- rolls on the line 4-4 of Fig'. 3;

Fig. 5 is a detail view of a work roll with the generatrix ofv its surface indicated thereon;

Fig. 6 is a section of the work roll along the longitudinal axisthereof; Fig. 'l is a diametral section of the work roll in a plane of the generatrix;

Fig. 8 is a detail view illustrating a yoke )in or trunnion 5 on'a mounting plate 6. To the inner face oi.' this mounting plate Gis secured -as-by screws 1, a yoke 8 whose ends 9 are split to receive the necks I of work rolls II j or bearings of said necks. T he portion of the stud near the mounting plate is screw threaded and pro vided with an adjusting nut I2 (see Fig. 9) that bears against the face of the side wall 2 of the frame. The end portion of the stud has an axial bore with an internal thread in which works a screw I3 which extends through a hole in the side wall and whose head is adapted to 'bear against the outer face of the side wall. 'I'he end of the side wall is provided with a threaded hole in register with the recess in which the stud ofthe mounting plate its and in this threaded hole is a set screw I4 that is'adapted to` clamp i the 'mountlngvplate in adjusting position. By this arrangement.' the mounting plate, together with the yoke and the workv roll may be adjusted crosswise of the machine.

Each roll yoke is adapted to be tilted to .an

adjusted position. For this purpose. arcuate slots I are cut through the back wall of the yoke and adjusting screws 1 extend through said .25

slots into threaded holes provided therefor inV the mounting plate. 'I'his arrangement permits the roll yoke to be adjusted and clamped in adjusted position. To facilitate such adjustment, each end of the yoke has a threaded link I1 pivotallyA connected thereto and extending up,- wardly through the top portion of the iframe` work. The free ends of the links are threaded and provided with suitable adjusting nuts I8.

'Ihe neck I0 of each work roll is c onnected to a source of power I9 by any suitable con- Nnections that will drive the work rolls simultaneously,4 as, for instance, by the shafting and universal joints 2|. In the construction shown in Fig. l, there are two-work rolls I I arranged to form a pass. The work rolls are disposed alongside each other with their axes A, B ijn planes parallel with each other and with the longitudinalaxis C of the pass of the mill-but the roll axes are tilted in their own planes ou't of parallelism with the longitudinal axis ofthe mill, the axis A of one roll being inclined to the same extent but in the opposite direction to that ofthe axis B oi.' the'v opposite workroll. Preferably the longitudinal axis of the pass is horizontal and the axes of the work rolls are in vertical planes, and in the present description they are asumed to be in such positions. By reason of their inclination in opposite directions from the horizontal, the work The surface 24 of each work roll -is an un parted hyperboloid otherwise known asa hyperboloid of revolution of one nappe or one sheet vof revolution of the type that is generated bya straight line G in a planeparallel to the axis A about which said plane revolves, said line Ga being inclined to the plane which passesA through said axis and-is perpendicular to the plane of the `line` G. I'he angle of .such inclination isv heref matter referred to as the skew angle S of the roll surface. Such surface is concaved endwise and has the characteristicthat throughout its circumference all elements of its surface, that is, all lines extending lengthwise of` its surface at an angle tothe plane of its longitudinal axis equal to said, skew angle S, are straight lines; and this is true whether the angle is: positive or negative. '/I'hemathematical formula for Athe surface of the work roll is l rife-X4 wherein A and B are positive constants and 1X, Y` and Z are the coordinates of points inthe surface referred respectively to three axes, each of which intersects the other two at right angles. Fig. 5 is a view of the side of a work roll embodying my invention with the generatrix or element thereof shown by a heavy line on the proximate with their axes in parallel lplanes (preferably vertical) and inclined-equally and in opposite directions to the axis of the pass of the mill so as to effect longitudinal feeding movement of the c straightv line contact with the work stock throughlco work stock W. Such inclination or feed 'angle F is ordinarily about 159 to 25. Such feed angle' F should ordinarily be equal to the skew angles of the surface of the work roll. With this ar' rangement, a horizontal planepassing through the longitudinal horizontalaxis of the mill 'pass will intersect the proximate surfaces of both of the work rolls in straight lines that are parallel with each other and with said longitudinal axis and are elements G of the surface of revolution. Accordingly, the pass of the mill is of even width throughout its length and the work rolls'mak'e out the length of the pass. A

These facts will be'clear hp on 'reference to Fig. `5. This figure shows a side view of a work roll withl a hyperboloidal surface conforming to my invention and arrangedwith its longitudinal axisl A horizontal. 'I'he line G indicates the straight line generatrix or element whose revolution about vthe axis A generates the surface of the roll. The angle that the generatrix o r line G makesl Y. with the-horizontal plane of the axis'A of the roll is vthe skew angle S of the roll surface If.;A

therefore, the longitudinal axis A ofthe rolllis -tilted in a vertical -plane to an amount equal to the skew an le S,then the straight line or generatrix G be es'herizontal. What is true with respect to one work roll is equally true with respect tothe other work roll;A that it, when it is tilted to ,an extent equal to the skew 'angle of` the roll, its straight line generatrix will behari- Vcount of the work rolls being inclined with ref'- gorge, the pressure vthereon is gradually relieved.

zontal along the surface nearest to the surface A of the adjoining roll. In these horizontal positions, the two straight line generatrices are parallel with each other; and they are also parallel 'with the axisl of the pass, because, by assumption, they are in planes parallel with the axis l.of the` pass.

LvThe operation of the mill is as follows: 'The place of no slippage betweenthe surfaces of the two work rollsis at or near the plane of intersection of -their axes A. 1 3 with a horizontal plane, that is, where the diameters of the surfaces of revolution are least, which place is herein referred to as the circle of the gorge H or pass. The

work rolls are accurately adjusted sothat the 15 distance between the surfaces of the work rolls at the circleof the gorge, H is the same as the diameter desired for the work stock to be put through themachine. Thev proper spacing apart of the planes of the two rolls axes A, B therefore, always equals the diameter of the circle of the gorge plus the diameter desired for the nished work. 1 i vAlthough the lines in which the horizontal plane of the longitudinal axis of the mill intersetsv the ladjacent surfaces o f the work rolls are straight ,lines parallel with said longitudinal axis, thedirection in` which the pressure is applied to the work changes continuously. On acerence to the longitudinal axis of the mill, and

consequently the reaction thrust between the rolls at Itheir ends is less than at the circle of the gorge, that is, the roll pressure'increases progressively as the bar or stock` proceeds through the pass. The maximum pressure is exerted at the no slippage point or circle of the gorge H. Consequently, it is easy for the work to'. enter the pass and after passing the circle of the 'I'he first effect of the workrolls -is to rotate the work and progress it longitudinally through the pass which extends substantially the vfull length of the work rolls.y At the circle of the gorge or pass, the points of contact of the work rolls with the work are in the same straight line that passes through the axes of the two work rolls and consequently pressure of the rolls Iis applied perpendicularly to'the surface of the work. This condition prevails only along the line which is the intersection of the planes in which the respective gorge circles lie, this line.

- being perpendicular' to the longitudinal axis of 'the mill. Inv all other planes perpendicular to'v such axis the radii of the two work rolls at their points 'of contact with the work are out of alinement with each other and with the line of pressure of the roll. In consequence of this condition, the effect of the pressure of the `work `roll on the rk isl reduced to that component thereo of vihicllA acts on the work along the line which"k brought to correct size byy pressure applied'ra- 70` dially or transversely to the longitudinal axis. Consequently, the sizing is accurate and uniform 'throughout the length of the work and, as

the work is not submitted to any considerable lonitudinal tension. there is no tendency toin- 75 tensify any surface defects in the work. At the n same time, the cross-rolling of the work has vuse on work of different diameters.

surface of the work and the rubbing action thus brought about serves to efiiciently polish the surface of the work. This rubbing action, along with the sizing'and truing action are helpful. in correcting minor kinks' and Jslight longitudinal curvature although the machine is neither `intended nor adapted to do the work of an ordinary straightening machine. On the other hand, it has no tendency to bend the Work, as in the case of die-drawing, and to a considerable extent makes it practicable to dispense with a separate straightening operation as may be necessitated by die drawing.

My machine is of universal application in the sense that the same rolls can be adjusted for For such adjustment, no change is made inthe angularity of the rolls, as the proximate elements of the rolls are parallelfor'tubes and bars of all diameters. All that is required, in such adjustment for size, is to move the rolls to positions distant from the axis of the pass equalto the radius desired for the tube or bar. It is also useful on steels or other metals that are of too low tensile strength to permit of cold drawing. On account of applying the pressure to the work transversely to the axis thereof, without any longitudinal skin friction, there is a minimum of molecular or interna] strain on vthe work with a minimum of4 structural diierentiation between the core and surface portion thereof.

While I have hereinbefore described my machine as having a set of two work rolls, it is obvious that three or more work rolls may be used in one set, if the work is of large enough diam- -eter to' permit them to contact with the work without interference with one another. Insuch case, the rolls are arranged at equal distances apart and are otherwise disposed as in the case of the tworoll set.

While my mill is especially useful for sizing tubes, it has'a tendency to increase the wall thickness thereof. I attribute this tendency to the fact that the lines of contact of. the work rolls with the stock in the pass are o f such great length as to oppose considerable resistance to elongation of the metal so that the metal is compelled to flow radially or transversely rather than longi tudinally and the length ofthe tube is shortened accordingly. Thus the degree of thiclceningof`v the tube wall may be governed by increasing or decreasing the length-of the straight line contact of the pass with the work so as to increase ordel crease the resistanceto the plastic flow of the metal of the `work longitudinally of the pass. Likewise, the mill has a cold working effecten the. work, that is it changes its physical characteristics. This cold working effect is subject to control.

. the rolls so as to decrease their resistance to the plastic flow of the metal longitudinally.' When,

ness of the tubes, the rolls should be made long enough to create such resistance to the longitudinal ow of the metal as to induce radial or transverse flow thereof.

What I claim is:

`1. A work roll whose work surface is a hyperboloid of revolution generated by a straight line in a plane parallel with the axis of the roll and intersecting 4an axial plane perpendicular to said first mentioned plane at an angle of from fifteen to twenty-five degrees, said surface being of the formula: Y Z,

wherein A and B are positive constants'and X, Y and Z are the coordinates of points in the surface referred respectively to three axes, each of which intersects the other vtwo at right angles.

2. A work roll whose surface is a hyperboloid of revolution with straight line elements, each element being in a plane parallel to the axis of said work roll and disposed at an angle of from fifteen to twenty-iive degrees to the plane of the axis perpendicular vto said first mentioned plane.

3. A machine for sizing, truing or polishing bars and tubes comprising a framework and work rolls rotatably mounted therein and arranged withv their axes inclined equally and in opposite directions in planes parallel to each other and to the longitudinal axis of the machine, the surface of said rolls being hyperboloids of revolution of the formula:

. a Y z,i

` is A wherein A and are positive constants and X, Y

CII

and Z are the coordinates ofizpoints in the surface referred respectively to three axes, each of which intersects the other two' at right angles.

4. A machine of the kind described comprising elongated rotatably mounted work rolls and meansfor driving same, said work rolls being' disposed with their axes in parallel planes butinclining in opposite directions', the surface of each. work 'roll being a hyperboloid of revolution generated by a straight line in a plane parallel with the axis of the roll and intersectingy an axial plane perpendicular to said first mentioned plane at an angle of from fteen to twenty-five degrees and the .inclination .of the axes of the rolls being equal to said` angle, whereby the distance between said rolls is uniform throughout the working` length of the rolls.

5. A machine for sizing, truing or polishingbars and tubes comprising a framework and work rolls rotatably mounted therein and arranged v alongside each other to form a longitudinal pass,

revolution of referred respectively to three axes, each of which intersects the otherl two at right' angles, said rolls having their axes in planes parallel to each other and to the longltjldinal axis of the pass and tilted in opposite 'directions in their planes at an angle equal to the skew angle of 'the work roll.

6. In a machine of the kind described, the com'- lsurface of the -bination of rotatably mounted work rolls and Cil means for driving same, said rolls being disposed with their axes in substantially parallel planes but inclining in opposite directions, the surface` of each work roll being a hyperboloid of rev-:ilution generated by a straight iine in a plane parallel with the axis of the roll and intersectingan axial plane perpendicular to said first mentioned plane at an angle oi from fteen to twenty-lve 7. A work roll'for sizingfftruing and polishing bars and tubes whose surface is a hyperboioid ofv revolution-whose mathematical formula is Y whereinl A and B are positive constants and X, Y.

and Z are the coordinates of points in the surface referred respectively to three axes,'each of which intersects theother two at right angles.

v WALTER SIEGEEIST.

CERTIFICATE oF coRREcT'IoN.

' Patent No. 2,152,976. l october 11, 1938. v l WALTER SIEGERIST.

It is hereby oertified that errorh appears in the printed speoification of the above numbered patent requiring correction as" follows: Page 2, first column, lines 9 and lO, strike ot the words lotvherwise known as a hyperboloid of' r41\gevol1.1t: n of vone nappe or one sheet" and insert the same after "revolution", line ll; page 5, secondoolumn', line )40, olaim 5,.' v"after "angles" and before the period insert the comma and Words the adjacent Henry Van Arsdal-e (Seal) Acting Commissionerof Patente. 

